检索结果-南通市图书馆

Experimental investigation of hypersonic flight-duplicated shock tunnel characteristics

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2021年第3期37卷 422-433,I0002页

作者： c K.Yuan Z.L.Jiang Institute of Mechanics Chinese Academy of SciencesBeijing 100190China University of chinese Academy of Sciences Beijing 100190China

Hypersonic air-breathing propulsion is one of the key techniques for future aviation and the ground aerodynamic testing for full scale test models with sufficient test time at flight conditions is of fundamental importance for verifying hypersonic air-breathing *** on the backward detonation-driven concept,the hypersonic flight-duplicated shock tunnel(or Jf-12 shock tunnel)has been successfully constructed and *** facility is capable of reproducing airflow for Mach numbers ranging from 5 to 9 at an altitude of 25-50 km,with a test duration of more than 100 *** quantify the performance of the shock tunnel,experiments were conducted to investigate the aerodynamic characteristics of the test flows and the effects of several critical techniques that play important roles in the operation of the shock *** stagnation pressure was constant within士5%and the average stagnation pressure varied by less than 0.048%/*** variation of the stagnation pressure in repeated experiments is less than 2.0%,indicating the good repeatability of the wind *** non-uniformity of the Mach number in the core flow field at the nozzle exit was within士2.5%.Additional,a uniform flow field is established upstream of the nozzle *** axial gradients of the flow field are small since the Mach number varies less than 1.7%/*** regarding the ignition technology,diaphragm ruptures,detonation driver capacity,incident shock-wave decay,and tunnel operation mode are also *** findings of this study are not only helpful for operating the shock tunnel,but can also assist the future development of hypersonic wind tunnels.

关键词： Hypersonics Shock tunnels flow characteristics

Prophylactic fixation of the unaffected contralateral side in children with slipped capital femoral epiphysis seems favorable:A systematic review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2022年第5期13卷 515-527页

作者： Steven J c Vink Renée A van Stralen Sophie Moerman christiaan J A van Bergen Department of Orthopedic Surgery Erasmus Medical CenterRotterdam 3015GDNetherlands Department of Orthopedic Surgery University Medical Center GroningenGroningen 9713GZNetherlands Department of Orthopedic Surgery Amphia HospitalBreda 4818CKNetherlands

BAcKGROUND Slipped capital femoral epiphysis(ScfE)occurs in adolescents and has an incidence of around 10 per 100000 *** presenting with a unilateral ScfE are 2335 times more likely to develop a contralateral ScfE than the general *** factors that have been suggested to increase the risk of contralateral slip include a younger patient,an underlying endocrine disorder,growth hormone use and a higher radiographic posterior sloping ***,there is still much debate on the advantages and disadvantages of prophylactic fixation of the unaffected side in an otherwise healthy *** To investigate the risk rate of contralateral ScfE and assess the(dis)advantages of prophylactic fixation of the contralateral *** A systematic literature search was performed in the Embase,Medline,Web of Science core collection and cochrane *** terms included‘slipped capital femoral epiphysis,’‘fixation,’‘contralateral,’and *** eligibility of the acquired articles was independently assessed by the authors and additional relevant articles were included through *** were considered eligible for inclusion if they presented data about otherwise healthy children with primarily unilateral ScfE and the outcomes of prophylactically pinning their unaffected side,or about the rates of contralateral slips and complications *** study quality of the included articles was assessed independently by the authors by means of the methodological index for non-randomized studies *** Of 293 identified unique publications,we included 26 studies with a total of 12897 patients.1762 patients(14%)developed a subsequent symptomatic contralateral *** addition,38%of patients developed a subsequent slip on the contralateral side without experiencing clinical *** most outspoken advantage of prophylactic fixation of the contralateral hip in the literature is prevention of an(asymptomatic)slip

关键词： Slipped capital femoral epiphysis Primary prevention Postoperative complications Risk factors Radiography

Repurposing of berbamine hydrochloride to inhibit Ebola virus by targeting viral glycoprotein

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2022年第12期12卷 4378-4389页

作者： Dongrong Yi Quanjie Li Han Wang Kai Lv Ling Ma Yujia Wang Jing Wang Yongxin Zhang Mingliang Liu Xiaoyu Li Jianxun Qi Yi Shi George f.Gao Shan cen Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences and Peking Union Medical SchoolBeijing 100050China cAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of chinese Academy of Sciences Beijing 100049China cAMS Key Laboratory of Antiviral Drug Research Institute of Medicinal BiotechnologyPeking Union Medical CollegeChinese Academy of Medical SciencesBeijing 100050China

Ebola virus(EBOV)infection leads to staggeringly high mortality *** and low-cost treatments are urgently needed to control frequent EBOV outbreaks in *** this study,we report that a natural compound called berbamine hydrochloride strongly inhibits EBOV replication in vitro and in *** work further showed that berbamine hydrochloride acts by directly binding to the cleaved EBOV glycoprotein(GPcl),disrupting GPcl interaction with viral receptor Niemann-Pick c1,thus blocking the fusion of viral and cellular *** data support the probability of developing anti-EBOV small molecule drugs by targeting viral *** importantly,since berbamine hydrochloride has been used in clinic to treat leukopenia,it holds great promise of being quickly repurposed as an anti-EBOV drug.

关键词： Ebola virus Drug repositioning Entry inhibitor Primed glycoprotein Structure-based virtual screening Protein-protein interaction Berbamine hydrochloride Natural compound

Simulation of Vortex convection in a compressible Viscous flow with Dynamic Mesh Adaptation

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2014年第5期6卷 590-603页

作者： c.H.Zhou Department of Aerodynamics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In this work,vortex convection is simulated using a dynamic mesh adaptation *** each adaptation period,the mesh is refined in the regions where the phenomena evolve and is coarsened in the regions where the phenomena deviate since the last adaptation.A simple indicator of mesh adaptation that accounts for the solution progression is *** generation of dynamic adaptive meshes is based on multilevel refinement/*** efficiency and accuracy of the present procedure are validated by simulating vortex convection in a uniform *** unsteady compressible turbulent flows involving blade-vortex interactions are investigated to demonstrate further the applicability of the *** results agree well with the published experimental data or numerical results.

关键词： Mesh adaptation vortex-convection blade-vortex interaction unsteady flow timedependent problem shock-vortex interaction.

Study of ultra-precision diamond turning of a micro lens array with a fast tool servo system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Study of ultra-precision diamond turning of a micro lens arr...

Short-term Effects of Tillage Practices on Organic carbon in clay Loam Soil of Northeast china

2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies

作者： S. To T.c. Kwok c.f. cheung W.B. Lee Advanced Optics Manufacturing center Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong Advanced Optics Manufacturing center Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong Advanced Optics Manufacturing center Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong Advanced Optics Manufacturing center Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong

＜正＞A Microlens array is a critical component for optimizing display functions. With the increasing usage of display systems in photonic products nowadays, more attention is being paid to the research and development of fabrication technology for microlens arrays. Ultra-precision machining with a fast tool servo （fTS） is one of the leading methodologies for fabrication of high-quality optical microstructural surfaces. fTS is an independently operated positioning device, which provides an indispensable solution for machining optical microstructures with sub-micrometer form accuracy and nanometric surface finish, without the need for any subsequent post processing. The surface quality of an fTS machined surface depends largely on the selection of cutting conditions. However, the achievement of ultra-precision surface finishing depends greatly on the experience and skill of the machine operators. Determination of optimal cutting conditions can stabilize the quality of the fabricated microlens array. In this paper, the effect of cutting conditions such as depth of cut, feed rate, spindle speed and surface speed are investigated;and optimal surface roughness and surface profiles in ultra-precision machining with fTS can be observed.

关键词： Ultra-precision machining fast Tool Servo Microlens array Surface roughness .

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Pedosphere 2007年第5期17卷 619-623页

作者： LIANG Ai-Zhen ZHANG Xiao-Ping fANG Hua-Jun YANG Xue-Ming c. f. Drury Northeast Institute of Geography and Agroecology Chinese Academy ofSciences Changchun 130012 （China） Graduate School of the chinese Academy of Sciences Beijing 100049 （China） Greenhouse ＆ Processing crops Research centre Agriculture ＆ Agri-Food Canada Harrow Ontario NOR 1GO （Canada）

一个耕种实验，由犁板组成犁( MP )，山脉耕种( RT )，和没有耕种( NT )，与四在一个使随机化的完全的块图案被执行复制在东北中国在粘壤土土壤的表面层( 30 厘米)在 SOc 内容和它的分发上学习3年的耕种管理的效果。NT 没与 MP 和 RT ... 详细信息

一个耕种实验，由犁板组成犁( MP )，山脉耕种( RT )，和没有耕种( NT )，与四在一个使随机化的完全的块图案被执行复制在东北中国在粘壤土土壤的表面层( 30 厘米)在 SOc 内容和它的分发上学习3年的耕种管理的效果。NT 没与 MP 和 RT 相比在表层土(0 5 厘米) 导致 SOc 的重要增加；然而，在 NT 土壤的 SOc 内容显著地在 5 20 厘米的深度被减少。因此，短期(3 年) NT 管理趋于成层 SOc 集中，然而并非必然增加它在为土壤的犁层的存储。

关键词：中国东北地区粘壤土土壤有机碳耕种模式短期效应

Genome-wide identification and in silico gene expression analysis of the related to ABI3/VP1(RAV)transcription factor family in barley(Hordeum vulgare L.)

在线全文

学校读者我要写书评

暂无评论

BIOcELL 2021年第6期45卷 1673-1685页

作者： cÜNEYT UÇARLI Department of Molecular Biology and Genetics Istanbul UniversityIstanbul34134Turkey

RAV(Related to ABI3/VP1)transcription factors are unique members of the AP2-ERf superfamily with AP2 and B3 domains and play important roles in the regulation of seed germination,plant growth,and stress *** the study,7 RAV genes,named HvRAVs,were identified in barley based on the available genome *** five of the seven HvRAVs were located on chromosome 3,HvRAV5 and HvRAV7 were located on chromosome 1 and 4,*** of the predicted HvRAVs were intron-less,except HvRAV2,which had one *** proteins have shown basic,instable,and hydrophilic *** AP2 domain specific RAYD and WLG motifs were detected in all HvRAV ***,B3 repression domain,R/KLfGV,is also found in the c-terminal of *** were found to have stress-related cis-acting elements,including MYB,MYc,and ***2 was predicted to have no GARE motifs,TATcccA or TAAcAA(G/A),and *** drought conditions,the expression level of HvRAVs did not significantly change in a drought-sensitive barley genotype,whereas HvRAV5 and HvRAV7 were dramatically down-regulated in a drought-tolerant *** of HvRAV5 was also inhibited by ***7 was strongly induced by plant pathogen *** HvRAV6 was induced by exogenous gibberellin application and during the germination ***,HvRAV6 transcript was detected higher than other HvRAVs in all stress and control conditions as well as during *** silico analyses have shown that HvRAVs play a role in response to different abiotic and biotic stresses as well as in plant ***,the extensive biological roles of HvRAV genes in plant development and in response to abiotic and biotic stresses need further investigation.

关键词： Barley RAV AP2 domain B3 domain AP2/ERf family cis-acting elements

Bi3+assisted luminescence in SrMoO_(4):Sm^(3+) red phosphors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2021年第11期39卷 1336-1343,I0002页

作者： Vaibhav chauhan Prashant Dixit Praveen c.Pandey Department of Physics Indian Institute of Technology(Banaras Hindu University)Varanasi221005UPIndia

In this paper,we report synthesis of pure SrMoO_(4),Sm^(3+)(1 at%-5 at%)doped SrMoO_(4)and Bi^(3+)(1 at%-3 at%)co-doped in 4 at%Sm^(3+)doped SrMoO_(4)(SrMoO_(4):4 Sm^(3+))phosphors by solution combustion *** X-ray diffraction(XRD)analysis reveals the tetragonal phase of all samples,also Bi^(3+)co-doping supports crystallite size growth and reduces lattice *** analysis of Sm^(3+)doped SrMoO_(4)ascertains a decrease in band gap and Bi^(3+)co-doping confirms the emergence of an absorbance peak at around 308 nm attributed to Bi^(3+)energy ***(PL)analysis ascertains an increase in emission peaks for Sm^(3+)doped SrMoO_(4)up to 4%concentration,which are attributed to an electron transition from 4 G5/2 to 6 HJ(J=5/2,7/2,9/2,and 11/2)energy levels of Sm^(3+)*** have explained the effects of Bi^(3+)co-doping on the luminescence of Sm^(3+)doped SrMoO_(4).The reduced microstrain and increased crystallinity of the phosphors as a result of Bi^(3+)co-doping and their correlation with the luminescence of Sm^(3+)ions are discussed.

关键词： SrMoO_(4):Sm^(3+) Bismuth ion Photoluminescence Absorption study crystallinity Microstrain

Primary dendrite growth kinetics and rapid solidification mechanism of highly undercooled Ti-Al alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第5期40卷 47-53页

作者： Z.c.Luo H.P.Wang Department of Applied Physics Northwestern Polytechnical UniversityXi’an 710072China

The rapid solidification processes of undercooled Ti-(47,50,54)at.%Al alloys were investigated by electromagnetic levitation(EML)method combined with a high-speed photoelectric *** maximum undercoolings of the three liquid alloys were 376 K,352 K and 316 K,*** processes corresponding to the primary dendrite growth and subsequent phase transition were recorded at various *** primary dendrite growth velocity V meets a double exponential relationship with the undercooling ***,a novel formula with physical meaning is proposed to explain that the more ordered liquid metal atoms accelerate the primary dendrite *** recalescences are found at all undercoolings for Ti-47 at.%Al alloy and at high undercoolings for Ti-50 at.%Al *** microstructures of solidified Ti-47 at.%Al alloys successively appear as coarse lamellar dendrites and finally evolve to refined parallel lamellar dendrites with the increasing *** T rises,the microstructures of solidified Ti-50 at.%Al alloys appear from coarse primary dendrites and interdendritic dendrites to refined lamellar *** the process from low undercooling to high undercooling,the primary phase of undercooled Ti-54 at.%Al alloys changes from r-Ti(r)to r-TiAl(r)and the microstructures of solidified alloys evolve from spherical primary dendrites and matrix phases to cellular dendrite ***,for the Ti-(47,50)at.%Al,the transformation temperature of metastable intermediateγphase decreases with the increase of ***,the microhardness of the three solidified alloys reaches the maximum when the undercoolings are 185 K,270 K and 316 K,respectively.

关键词： Electromagnetic levitation Rapid solidification Dendrite growth Microstructure Microhardness